Method of killing weeds and influencing plant growth



United States Patent Ofifice 3,063,823 Patented Nov. 13, 1962 3,063,823 METHOD OF KILLING WEEDS AND INFLU- ENCING PLANT GROWTH Engelbert Kiihle and Werner Schfifer, Koln-Stammheim, Ludwig Eue, Koln-Mulheim, and Richard Wegler, Leverkusen, Germany, assignors to Farbenfabriken Bayer Aktiengesellschaft, Leverkusen, Germany, a corporation of Germany No Drawing. Filed Jan. 16, 1958, Ser. No. 709,169 Claims priority, application Germany Jan. 21, 1957 8 Claims. (Cl. 712.6)

The present invention relates to and has as its objects agents for killing weeds and influencing plant growth and a method of employing same. The inventive compositions contain as essential active ingredients carbamide oximes of the following general formula In this formula R R and R stand for the following groups: hydrogen, low molecular weight alkyl groups of maximum 8 carbon atoms (R R and R may also be different), R and R may also be linked to one another, as for example in the cyclohexane or cycloheptane radical, they may also be unsaturated alkyl groups, alkyl groups being substituted by hetero atoms such as halogen or nitrogen, alkyl groups broken up by hetero atoms such as ether groups, alkyl radicals with or without substituents (halogen, nitro, alkyl, hydroxy or alkoxy groups being chiefly the substituents), heterocyclic radicals such as the'pyridine or furan radical. R may also be an aryl radical. R may also be an aryl or alkyl radical being linked to 2 amino groups at the same time thus including compounds which contain twice the carbamideoxime group.

The production of these compounds is carried out in a known manner by conversion of the corresponding oximes, with isocyanates, for example as described by Goldschmidt (Ber. 22 [1889], pages 3101-3114) and Petersen (Ann. 562 [1949], Page 213).

The herbicidal composition of the present invention may be prepared by usual methods, i.e. preferably by mixing the active ingredient with solid or liquid carriers or conditioning agents as they are used as pest control adjuvant or modifiers for formulations adapted for the application to soil, weeds or unwanted plants using ap plicator equipments. Solid compositions are preferably in the form of dusts and are compounded to give homogeneous free-flowing dusts by admixing the active compound with finely divided solids preferably talcs, natural clays, pyrophyllite, diatomaceous earth, and flours such as walnut shell, wheat, redwood, soya bean, cottonseed flours, and other inert solid carriers of the kind conventionally employed in preparing pest control compositions and dusts or powdered form.

Liquid compositions employing the active ingredients are prepared in the usual way by admixing the active ingredient with a conventional liquid diluent media. The active ingredients .are quite insoluble in most liquids although solutions containing them at low concentration can be made if desired using various of the common organic solvents such as cyclohexanol, acetone, ethanol, isobutanol, furfural, isopropyl acetate, and the like. More preferably, the liquid compositions are prepared in more concentrated form so that the liquid composition is primarily a suspension of the active compound in the liquid. In preparing such compositions conventional spray oils, alkylated naphthalene, or fats, or similar vehicles such as cottonseed oil, olive oil, lard, paraffin oil, hydrogenated vegetable oil and similar conventional organic liquid diluents are suitably employed.

The herbicidal compositions of the invention whether in the form of dusts or liquids preferably also include a surface active dispersing agent of the kind sometimes referred to in the art as wetting, dispersing, and emulsifying agents.

The surface active dispersing agents employed can be of the anionic, cationic, or nonionic type and include for example, sodium oleate, sulfonated petroleum oils, sodium lauryl sulfate, polyethylene oxides, and other surface active dispersing agents such as those listed in detail in articles by McCutcheon in Soap and Sanitary Chemicals, August, September, and October of 1949.

The amount of surface active dispersing agent employed in compositions of the invention will vary depending upon the effectiveness of the particular surface active dispersing agent employed and the properties of other materials in the composition. Generally, the surface active dispersing agent will not comprise more than about 30% by weight of the composition and with the better materials will be 5% or less.

The content of the active ingredient employed in the herbicidal compositions of the invention will vary according to the manner in which and the purpose for which the composition is to be applied but in general will be from 0.5 to by Weight of the composition.

The herbicidal compositions are applied either as a spray or in the form of a dust to the locus or area to be protected from undesirable plant growth. The active ingredient is, of course, applied in amount sufiicient to exert the desired plant killing action. The application can be made directly upon the locus or area during the period of infestation of unwanted plant growth or alternatively the application can be made in advance of an anticipated infestation.

In applying the herbicidal compositions of the invention for selective weed control as in the control of weeds in cotton or corn fields, the compositions are preferably applied after planting of the crop seeds but before emergence of the seedlings. In other words, the applications are of the pre-emergence type.

Fertilizer materials, other herbicidal agents, and other pest control agents such as insecticides and fungicides can be includedin the herbicidal compositions of the invention if desired.

The above mentioned compounds act particularly on dicotyledonous plants such as cress, mustard and charlock, their action is selective, and therefore the combating of weeds can be effected in corn or green land with protection of the cultivated plants. With increased concentration also monocotyledonous plants can be destroyed so that at an appropriate concentration the compounds are also suitable for total weed control.

As Weeds as defined by the application there are to be understoodplants which grow in places Where they are not desired. Representatives of the above listed class of compounds act as herbicides already at low concentration. It has further been found that seedlings and young plants of certain species are damaged to a large extent or destroyed. After treatment of the soil, it is thus possible to prevent germination of the seed.

In most cases the best treatment is the use of the aqueous emulsions of the inventive active ingredients since thereby distribution in the soil is most efllciently accomplished. Such aqueous emulsions may be prepared as described above from either pure active ingredient-auxiliary solvent-emulsifier-pre-mixtures or from dusts containing additional emulsifiers.

The destruction of the weeds can take place at any stage weeds may consist of a mixture of various of the aforeu said compounds and a solid or liquid diluent, to which known herbicides or fertilizers may be added.

The following examples are given by way of illustration only without, however, limiting the present invention thereto:

Ex mp e 2.

Emulsions have been prepared from N-phenyl-carbamide acetone oxime as shown in Example 1; such solutions containing 0.01% of activeingredient completely destroy mustard and charlock when used in an amount of 1000 Example 1 litres per hectare. At this concentration oat is not dam- 100 mg f N Pheny1 carbamide acetone Oxime are aged. With concentrations of 0.5% also oat is destroyed. mixed with 3 ml. of acetone. 2 drops of benzyl hydroxy Example 3 diphenyl polyglycol ether (containing about 15 glycol 0 1 1 residues) are added. This premixture is further diluted 2 or emulsions of N' m' carbamldle with Water to a volume of 100 ml. This aqueous solution acetone Qxlms are Prepared desqnbed P is applied to mustard and oats as follows: in the green p g en h p yed drtp wetwithhthis so u}-1 house young mustard plants (with 2 leaves) and oat of s S complete defohanon of t e Frenc about cm. high are sprayed with the solutions as pre- 15 can-S e5 p E 1 I 4 pared above. After 14 days the percentage of damage of p e the plants has been determined, the results having been Activities of the active inventive compounds in nasturtaken from Sparalleltests. tium plant tests, oat-mustard pre-emergence tests, oatmustard post-emergence tests, and Phaseolus vulgaris tests Percent damage with 0.1% emulsions: Percent are to be seen from the following table. (The abbrevia- Mustard 100 tion before the figures under mustard and oat mean Oat 0 m=mustard and o=oat.)

nasturtium mustard-oat- Phasei plant test, pro-emergence olus, 0a 3,

Has

/C=N-O(f'-NH 0 m 3, o 0 4 m s, o 0 H 0 H3C\ /C='NO(NH-CH3 o In a, o o 2 m 34, 0 0 H36 H3O CH3 /G=N-0(fi-NH C\ 3-4 m 3, 0 0 H30 0 CH;

C=NO---CNH 0 m 2, o 1 ll HsC 0' l /G=NO(I%-NH 0 1 in 4-5, 0 0 HaC O l Cl HaC\ l C=NO(l?-NE 3 m 0-1, 0 l. 0 H30 0 C=NOCNH C1 2-3 O- m 4, 0 1 ll HaC C=.N0fi-NH Cl 0 0 m 23;0 0 H30 0 i HaC\ /C=NO%|,NH 0CzHs m 2%, 0 1-2 0 m o, o 0 H30 0 H3C\ C=N-O("J-NH-(CHn)r-Ol 2-3 0 Ha HQC\ /C=N-O(l'lJNHCHrCH:0-COz-Cl 0 m 3, 0 3 2 0, 0 H20 0 nasturtium mustard-oat- Phaseg plant test, pro-emergence olus oatpos 0.005% 0.1% 0.1 emergence HsC C=NO("JNH O In 2, o 1-2 m 1, o 1 HsC-Ca 0 o=N-0- :NH 0 o 1111,01 H:CCH2 0 /C=NO(fi-NH o1 1 m a, o 1 HaC-CH: O

C g- O 0 M Solutions of the active ingredients for the foregoing We claim:

tests have been prepared exactly as described in Example 1. The nasturtium plant test have been carried out for determination of inhibiting plant growth as follows: nasturtium seeds are placed on filter paper in glasses of about 5 inches height and about 2 inches diameter in such way that the filter paper is partially placed in a solution containing the active ingredient of the concentration indicated above. Evaluation of growth of the nasturtium seeds occurred after 6 days. The figures in the column under nasturtium plant test mean:

O=no effect 1=slight inhibitation 2=strong inhibitation 3=very strong inhibitation or no germination As test compound there has been used the sodium salt of pentachloro-phenol which has the evaluation No. 3.

Tests on Phaseolus vulgaris and on mustard oat postemergence have been carried out by spraying young plants of about 5 to 6 inches height drip wet. Evaluation occurred after 20 days. The evaluation numbers mean:

0=no effect 1=some spot burnings 2=severe burning damage of leaves 3=some complete damage of leaves and some slight damage of vegetation points 4=leaves partially destroyed 5=complete killing of plants As test compound there has been used the sodium salt of 2,4-dichlorophenoxy acetic acid Which has the evaluation No. on Phaseolus=5, and on mustard-oat postemergence=m 5 o 0.

Pre-emergence tests on mustard-oat have been carried out as follows: 24 hours after sowing of oat and mustard in normal soil, the soil area has been sprayed with an aqueous emulsion containing the active ingredient in a concentration as shown in the above table. Evaluation occurred after days. Control check up has been carried out after days. The evaluation numbers mean:

0=no effect 1=damage of first leaves 2=damage of young plants and growth inhibitation there- 3=no growth of plants or young plants killed at least 20 days after germination As test compound there has been used N-p-chlorophenyl- N',N'-dimethyl urea, which has the evaluation No. on mustard-oat: m 3 o 3, and dinitro-o-cresol, which has the evaluation No. on mustard-oat: m 3 o O.

1. A method of killing weeds and inhibiting plant growth which comprises treating the plants with an effective amount of the compound of the formula 3. A method of killing weeds and inhibiting plant growth which comprises treating the plants with an effective amount of the compound of the formula 4. A method of kiling weeds and inhibiting plant growth which comprises treating the plants with an effective amount of the compound of the formula 5. A method of killing weeds and inhibiting plant growth which comprises treating the plants with an efi'ective amount of the compound of the formula CEa CH3 OH: 0 CH 6. A method of killnig weeds and inhibiting plant growth which comprises treating the plants with an effective amount of the compound of the formula 7. A method of killing weeds and inhibiting plant growth which comprises treating the plants with an efiective amount of the compound of the formula 8. A method of killing weeds and inhibiting plant growth which comprisestre-ating plants with an efiective amount of a compound of the following general formula:

in which R and R are each selected from the group consisting of hydrogen, lower alkyl radicals having up to 8 carbon atoms and a phenyl radical; and R is selected from the group consisting of lower alkyl radicals having up to 8 carbon atoms, lower chloroalkyl chloroacetoxyethyl, phenyl, lower alkyl-substituted phenyl, chlorophenyl, lower alkyl-substituted chlorophenyl and lower alkoxy phenyl,

References Citedirr the-file of this patent- UNITED STATES PATENTS M0yer Feb. 18, 1947 Sowa Nov. 6, 1956 OTHER REFERENCES Goldschmidt in Ber. 22, 1889, pages 31013114. Brady et al. in Chemical Abstracts," Vol. 10, 1916,

10 pages 2578 and 2579. 

8. A METHOD OF KILLING WEEDS AND INHIBITING PLANT GROWTH WHICH COMPRISES TREATING PLANTS WITH AN EFFECTIVE AMOUNT OF A COMPOUND OF THE FOLLOWING GENERAL FORMULA: 